An important goal of neuroscience is to understand the neural mechanisms by which organisms detect and represent sensory experiences. There is compelling evidence that the mushroom bodies of the insect brain participate significantly in olfactory and memory functions. These structures, in important ways, resemble mammalian brain areas believed to perform similar functions. The mushroom bodies thus serve as a relatively simple model for olfactory and memory processing with odorant serving as a natural, behaviorally relevant form of sensory stimulation. In the locust mushroom bodies, as in mammalian pyriform cortex, odors induce synchronous neuronal activity detectable as tightly coordinated activity among individual neurons, and as oscillating local field potentials. This synchronous activity changes as the animal acquires experience with a given odorant. The goal of the current project is to investigate how this neural synchrony is generated, what functions it might subserve, and where some forms of synaptic plasticity may reside in this system. These studies will employ extracellular and intracellular recording techniques to examine the contributions of specific classes of interneurons to the odor-induced oscillations in the presence of both novel and familiar odorants. The analysis will likely reveal general features of coordinated neuron assemblies involved in sensory processing and memory.